This invention relates to a wear-resistant element. It further relates to a mould for making such an element and to a support frame for such an element. It relates in particular to a wear-resistant element which is a screen for separating particulate material, and to a wear-resistant element which forms a wear-resistant lining, covering or wall.
According to the invention there is provided a wear-resistant element having protrusions adapted to clip into corresponding openings in support means to thereby releasably secure the element to the support means.
The element and the protrusions may be integral. They may conveniently be of a synthetic plastics material such as polyurethane and may accordingly be integrally moulded in one piece, for example by injection moulding. A supporting element, such as a metal grid may be embedded in the element.
The protrusions may be slightly off-set with respect to the corresponding openings in the support means to thereby tension the screening element when it is secured to the support means. The protrusions may further be of a slightly larger size than the openings, thereby ensuring a tight interference fit.
The element may be of substantially rectangular panel-like form, having width and height dimensions substantially greater than its thickness.
When the element is in the form of a panel it may have a first surface which is subjected to wear and a second opposite surface which may be adapted to abut the support means.
The protrusions may have formations adapted to engage with a side of the support means opposite to the side to which the element is secured. Thus the protrusions may be substantially mushroom- or hook-shaped.
The protrusions may be tapered outwardly around their bases to correspond with tapering bores of the corresponding openings in the support means. The protrusions may further be provided with grooves enabling the protrusions to be compressed to facilitate removal of the protrusions from the openings.
The support means may be in the form of a frame, or substantially solid except for the openings adapted to engage the protrusions.
The sides of the element may have locating formations thereon, to engage with corresponding formations on the support means, further to locate and support the element.
The wearing surface of the element may be smooth, or it may have formations thereon such as ridges, cavities, or ribs, depending on the particular application.
Also according to the invention there is provided a mould for making a wear-resistant element according to the invention.
Further according to the invention there is provided support means for supporting a wear-resistant element in accordance with the invention, the support means having a plurality of openings therein adapted to engage with the protrusions on a wear-resistant element in accordance with the invention to thereby clip the element to the support means.
The openings may have tapered rims.
The support means may be a frame, a panel or a latticed structure.
It is known by the applicant that screens used for screening ore in mining operations are provided in separate sections that are secured to a supporting frame. However, due to the problem of properly tensioning these sections, the sections are of relatively large sizes, for example 180cm by 120cm. If a part of a section becomes worn or damaged, the entire section must be replaced although the worn or damaged part may constitute only a small area of the entire screen section. This results in a waste of material and tends to increase the cost of the operation.
Furthermore, the sizes of the vibratory frames tend to vary from customer to customer so that a manufacturer is forced to manufacture and maintain in stock a range of screen sections of different sizes in order to be able to satisfy his different customers.
Some of the methods known to the applicant of securing the screen sections to the supporting frame tend to obstruct a relatively large part of the screen section, thereby resulting in a relatively smaller portion of the screen section which is available for screening the particulate material. This also requires that the individual screen sections are relatively large.
The invention accordingly extends to a screening element comprising a wear-resistant element in accordance with the invention, the wear-resistant element being provided with screening apertures.
The screening element may have an upstream side and a downstream side and the screening apertures may diverge from the upstream side to the downstream side.
Further according to the invention there is provided a screen comprising a supporting frame having a plurality of apertures therein, and a screening element in accordance with the invention secured over each aperture, the screening element being secured to the supporting frame by means of the protrusions on the screening element being engaged with the support frame.
The protrusions may be clipped into corresponding openings provided around the apertures in the support frame.
The protrusions of adjacent screening elements may be clipped into the same openings in pairs.
The protrusions on the screening elements may be off-set with respect to the openings in the support frame to thereby tension the screening elements on the support frame.
Further according to the invention there is provided a wear-resistant lining which includes at least one wear-resistant element in accordance with the invention.
The lining may further include support means and a plurality of the wear-resistant elements secured thereto by means of the protrusions on the wear-resistant elements being engaged with the support means.
Still further according to the invention there is provided a covering or wall which includes a plurality of wear-resistant elements in accordance with the invention.
A wear-resistant element in accordance with the invention may be employed to line bins, chutes and the like in which abrasive granular materials, such as crushed mineral ores, are stored or conveyed, such as in mining and ore refining and crushing operations.